Automatic electric switch.



No. 872,215. PATENTBD NOV. 26, 1907. W. L. BLISS.

AUTOMATIC ELECTRIC SWITCH.

APPLICATION TILED JAN. 6. 1905.

WILLIAM L. BLISS, 0 F BROOKLYN, NEW YORK.

AUTOMATIC ELECTRIC SWITCH.

Specification of Application filed January 6.

Letters Patent.

1905. Serial No. 239.927.

Patented Nov. 26, 1907.

Too whom it may concern: Bc'it known that I, WILLIAM L. Buss, a citizen of the United States, residing at Brooklyn, in the County of Kings and State of New 1' ork, have invented new and use ful Improvements in Automatic Electric Switches, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forminga part of this specification.

The present invention relates to improvements in automatic electric switches which are particularly adapted to be employed in car lighting systems.

In s stems of car lighting employing a generator and a storage battery for operating the lamps, it is usually necessary to provide an automatic switch which will connect the storage battery and the lamps to the generator. when the generator is operative and which will disconnect the storage batter and the lamps from the generator when the generator is inoperative. The automatic switch which is usually employed for this purpose is provided with a winding of comparatively hi h resistance connected in shunt across t e terminals of the generator and another winding. of comparatively low resistance connected in series with the generator andv the storage battery. When the voltage of the generator is equal to the voltage of the battery, the shunt windin causes the switch to close. The series winr mg will assist the shunt windin in keeping the switch closed so long as t e generator sends current through the series winding; but when the generator voltage falls below the battery voltage so that current from the bat tery will flow backward throu h the series winding, said series winding wil oppose said shunt winding, thereby causing the switch to '0 en.

The present invention relates particularly to a switch such as has been characterized, and it has for the object thereof to provide means which will reduce the current flowin through the shunt windin after the switc closes, and thus prevent t e shunt solenoid from becoming overheatedby an excessive current flowing throu h the same, and also reduce the current which must flow backward through the series winding from the battery to cause the switch to open.

The accompanying drawings illustrate a system of car lighting wherein an automatic trates a switch which has been de switch made in accordance with the present invention is employed. It will be under stood, of course, that the switch may be applied to other purposes, and, further, that it may be constructed in various W8.:'S.

The views in the drawings are as follows:

Figure l'illustrates a car lighting system PTOVIdBd with an automatic switch em )odymg the present invention, and Fig. 2 illusveloped for practical purposes, said switch being shown in section.

The system shown in the drawin s is provided with a generator 1, a storage attery 2 and translating devices 3, said storage battery and said translatin devices being connected to .said generator y mains 4 and 5 of a supply circuit. The storage battery and lamps are preferably connected in circuit in parallel, and the circuit of the lam s is preferably controlled by a switch 6. Iiit is necessary, a suitable automatic regulator may be provided to confine the output of the generator within prearranged limits, and another automatic regulator may be provided to re ulate the voltage impressed upon the trans ating devices.

The automatic switch which controls the supply circuit may be provided with stationary contacts 7 and 8 arranged in the supply circuit, and a movable contact 9 adapted to engage said stationary contacts and made of flexible material. The movable contact may be carried b a core or plunger 10 which may be surroun ed by windings 11 and 12, said windings being provided to operate the switch. The winding 11 is preferably made of fine wire and connected in a shunt-circuit 13 which extends across the supply circuit or generator terminals, and the winding 12 is preferably made of coarse wire and arranged in the supply circuit in series with the switch contacts.

Whenever the voltage of the generator is equal to or greater than that of the battery, the winding 11 will raise the plunger 10, thereby bringing the movable contact 9 into engagement with the stationary contacts 7 and 8 to close the supply circuit. The generator may then send current from the positive terminal thereof through supply main 4, winding 12, switch contacts 7-98, thence dividingl through the storage battery 2 and the trans ating devices 3, and finally through supply main 5 to the negative terminal therethe series. winding of. So long as the generator sends current through the supply circuit, theaction of the shunt winding 11 will be sup lemented by the action of the series win ing 12. But when the battery sends current backward through the supply circuit, which occurs when the 7 generator voltage is less than the battery volta e, the action of the shunt wind-ing ll wi i be opposed by the action of 12, and in consequence, the plun er 10 will fall, thereby removing the mova le contact 9 from engagement with the stationary contacts 7 and 8. The switch will thus operate to connect the storage battery' and the translating devices to the gen: erato'r' whenever the generator voltage is equal to or greater than that of the battery, and to disconnect the storage battery and the translating devices from the generator when .everthe voltage of the generator is less than that of the battery. 3

n The shunt circuit 13 is, preferably provided with a resistance 14 which is arranged in series with the shunt winding 11. "An auxiliary switch which is provided with a station-' ary contact 15 connected to the end of said resistance and. a movable contact 16 con- .nected to the other end of said resistance by a flexible connector 17 is employed to short circuit said resistance.

The movable contact is preferably loosely mounted upon a tail rod 18 which ismount edupon the plunger 10, said tail rod being preferably rovided with collars 19 and 20', between w ich saidmovable contacts may move. When the plunger is down and accordingly the main switch is open, the auxiliary switch will close a short circuit around the resistance '1 The energizing current for the shunt winding may then flow from the positive terminal 0 the generator through the shunt winding 11, flexible connector 17, movable contact 16 and stationary contact 15 to the ne ative terminal of the generator; When the plunger is up and accordingly the main switch is" closed, the auxiliary switch will be open and the resistance 14 will be in series with the shunt winding.

The collar 19 normally rests upon themov-.

able contact 16 and thereby determines the lower position of the plun er 10. The collar 20 is located upon-the tall rod 18 at such a distance from thecollar 19 that a certain,

amount 'of upward'motion of the plunger is permitted before the collar 20 engages the movable contact 16 and thereby opens the auxiliary switch. The movable contact 9 will spring upwardly at the center after it engages the stationary contacts, and thus the plunger. 10 vwill be permitted to rise until the movable contact '16 is raised from the sta-' tionary contact 15. The resistance 14 being in circuit after the auxiliary switch opens, the current flowing throulgh the shunt winding will be decreased. e strength of the shunt winding bein thus decreased and a,

downward pressure eing exerted upon the plunger by""the retractile force of the movable contact 9-, 'it will require only'a moderate amount of current to flow through the series winding 111 a reverse dlrection toneutralize'thef'effect of the shunt-winding and thus cause the plunger to'inove downwardly and thereby: open the main switch. I Upon the downward movement of the plunger, the movable contact 16.' will. remain out of engagement' with the. stationary contact 15 until the movable contact 9 is just'aboutto leave the stationary contacts 7 and 8.

to be made comof said windings -in this wayer makes it possi- The stationary contacts 7 and 8 lun er 10.n1aybe arra ed within'atube'22 P g v of non-magnetic materia The switch of the present invention may be applied to purposes other than those which have been set forth herein audit will be understood that the switch may be constructed in various ways,

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: I

1. In 'an automatic electric switch, in

combination, a winding adapted to be con- 7 nected in circuit inshunt,a winding adapted to be connected in circuit in series, a IXIQV? able switch element ada ted to be operated by said windings, said s unt winding being adapted to operate said switch. element to close said switch initially, and automatically operated means adapted to reduce the cur& rent flowing through said shunt winding from an operating current to a retaining current while-the switch is closed.

-2 In an automatic electric switch, in combination, a winding adapted to be connected in circuit in shunt, awinding adapted to be connected in circuit in series, a switch element adapted to be, operated by said 7 windings, a resistance arranged in series with said shunt winding, an auxiliary switch adapted to short circuit said resistance, and

a mechanical connection between said switch element and said auxiliary switch.

3. In combination, a generator, a storage battery, translating devices, a supply circuit connecting said storage battery and said translating devices to said generator, a wind- 'ing arranged in shunt with said generator,

a winding arranged in series with said genoperated by said erator and said storage battery, a movable contact controlling said supply circuit and windings, a resistance arranged in series with said shunt winding, an auxiliary switch adapted to short circuit said resistance, and a mechanical connection be tween said movable contact and said auxiliary switch, said connection being adapted to open said auxiliary switch when said movable contact closes said supply circuit.

4. In combination, a main switch having a movable contact,;a winding .adapted to be connected in circuit in shunt, a winding adapted to be connected in series, said windings bein adapted to operate the movable contact 0? said main switch, a resistance arranged in series with said shuntwinding, an auxiliary switch having a movable contact and adapted to short circuit said resistance, and a mechanical connection between the movable contact of said main switch and the movable contact of said auxiliary switch, said mechanical connection being adapted to 0 en the auxiliary switch upon the closing of t e main switch.

5. In an automatic electric switch, in con'ibination, a winding'adapted to be connected in circuit in shunt, a winding adapted to be connected in'cii'cuit in series, a main switch having a movable contact, said movable contact-being operated by said windings, a resistance arranged in series with said shunt winding, an auxiliary switch adapted to short circuit said resistance and having a movable contact, a mechanical connection between the movable contact of said main switch and the movable contact of said auxiliary switch, said mechanical connection being adapted to permit suflicien't freedom of movement between said movable contacts to allow said main switch to close before said auxiliary switch opens.

6. In cm ination, a main switch, a winding adapteu to be connected in circuit in shunt, a winding adapted to be connected in circuit in series, said main switch being operated by said windings, a resistance arranged in series with said shunt winding, an auxiliary switch adapted to close a short circuit around said resistance, means for o erating said auxiliary switch to open said short circuit upon the closing of said main switch, said means being adapted to open said auxiliary switch after the main switch closes.

7. In combination, a main switch, a winding made of comparativel fine wire, a winding made of comparative y coarse wire, said main switch being operated by said windin s,

a resistance arranged in series with t e former winding, an auxiliary switch adapted to close a short circuit around'said resistance, a mechanical connection arranged between said mai'n switch and said auxiliary switch and adapted to operate said auxilia switch to open said short circuit upon the c osing of combination, stationary supply circuit and operated by said ing current to a retaining current after said 1 movable contact closes said supply circuit. 9. In combination,

a generator, a storage battery, translating devices, a supply circuit connecting said storage battery and said translating devices to said generator, a winding arranged in circuit in shunt with said generator, another winding arranged in circuit'in series with said generator and said storage. battery, a movable contact adapted 'to control said. supply circuit and operated by said windings, a resistance arranged in series with said shunt winding, a movable switch contact controlling a short circuit around said resistance, a mechanical connection between said movable contacts adapted to operate the latter movable con tact to open said short circuit upon the oper ation of the former movable contact to close said supply circuit, said mechanical connection being adapted to permit suflicient freedom of movement between said contacts to allow the former movable contact to close said supply circuit before the latter movable contact opens said short circuit.

10. In an automatic electric switch, in contacts, a movable contact adapted to engage said stationary contacts, a plunger having said movable contact carried thereby, a winding adapted to be connected in circuit in shunt, a winding. adapted to be connected in circuit in series, said plunger being operated by said windings, a movable contact for closing a short circuit around said resistance while the former movable contact is out of engagement withsaid stationary contacts, the latter' movable contact being movably mounted u on said plunger, and a stop carried by said p unger and adapted to engage the latter movable contact to operate the same to open said short circuit after the former movable contact engages said stationary contacts.

combination, stationary contacts, a movable contact adapted to connect said stationary contacts, said movable contact being made. of flexible material and having the ends ithereof adapted to engage said stationary contacts, a plunger having said movable 11. In an automatic electric switch, in"

a connected to the central portion of saidcontact carried thereby, said plunger being movable contact, a winding adapted to be connected in circuit in shunt, another windmg adapted to be connected 1n circuit in series, said plunger being actuated by said windings, a resistance arranged in series with said shunt winding, a movable contact for closing a short circuit around said resistance while the former m wable contact is out of engagement with said. stationary con tacts, the latter movable contact being movably mounted'upon said plunger, and a stop carried by said plunger, said stop being adapted to engage the latter; movable ,contact to operate the same to open said short circuit around said resistance after the for mer movable contact engages sail stationary contacts.

12. In an automatic electric switch, in combination, stationary contacts, a movable contact adapted to engage said stationary contacts, a lunger having said movable contact carrie thereby, a winding adapted to be connected in circuit in shunt, another winding adapted to be connected in circuit in series, said plunger being operated by said windings, a resistance arranged in series with said shunt winding, a movable contact for closing a short circuit around said resistance while the former movable contact is out of engagement with said stationary contacts, a

tail rod mounted upon said plunger andhaving, the latter movable contact movably mounted thereon, and a stop carried by said tail rod and adapted to engage the latter movable contact to open said short circuit he a after, the former" movable contact a engages said stationary contacts.

13. In an automat1c electric switch, in

combinat on, a winding adapted to be connected in circuit in shunt, another winding 1 in circuit in series,

adapted to be connecte 'the former winding arranged within the latter wmdmg,

a movable switch element operated by said windings, said switch element being operated by said shunt winding to close the said switch initiallyfand means for reducing the current in said shunt winding after the switch is closed.

I4. In an electric switch in combinatioma frame, a plunger, a movable contact connected to said plunger and adaptedto engage stationary contacts, a winding adapted to be connected in circuit in shunt, another winding adapted to be connected in'circuit in series, said shunt winding and said series winding being arranged one within the other and carried by said frame and said plunger being surrounded by said windings,

witnesses. K

WILLIAM L. BLISS.

Witnesses J. H. ROBERTSON, HERBERT J.SM1'r1-I. 

